Vapor deposition may be employed in various surface treatments including etching, coating deposition, and cleaning. Vapor deposition processes include chemical and physical processes. Generally, in chemical vapor deposition a gaseous precursor is provided to a reactor containing a substrate. The gas reacts or decomposes to treat a surface. In physical vapor deposition a metal or ceramic may be ejected from a source and deposited on a substrate surface to form a coating. Various combinations of chemical and physical vapor deposition processes may be utilized as well. Coatings deposited in these processes may improve the wear resistance, oxidation characteristics, hardness, purity, or lubricity of the surfaces that are treated.
Plasma may often be generated during vapor deposition from precursors or inert gasses to assist in surface modification. The plasma may be generated through the application of an electric current, often at radio frequencies, to a coil or a pair of electrodes proximal to the gas. The gas may then be ionized and form a plasma. However, the processing chamber may need to be maintained at pressures of 1 mTorr to 50 mTorr. Further, the coil or electrode geometry may limit the source to substrate distance. In addition, the processing temperatures of some plasmas may be relatively high, greater than 300° C., and degrade the substrates. Accordingly, room for improvement remains in the development of chemical vapor deposition processes.